Process for steam jet texturing a coated yarn

ABSTRACT

A synthetic fiber finish which provides improved processing performance, heat stability, and the like, and comprises a heat stable, hydrophobic fatty acid ester lubricant a heat stable, hydrophilic antistat of an alkoxylated polyhydric alcohol-fatty acid ester or an alkoxylated alcohol ester; and a heat stable, hydrophilic emulsifier comprising alkylene oxide condensate of polyhydric alcohols and/or long chain fatty acid esters or alkylene oxide condensates of an alkaryl hydroxy-terminated compound.

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[111 3,827,114 [451 Aug. 6, 1974 PROCESS FOR STEAM JET'TEXTURING A COATED YARN Inventor: Roger John Crossfield, Charlotte,

Assignee: Fiber Industries, Inc., Charlotte,

Filed: Sept. 7, 1971 Appl. No.: 178,437

US. Cl. 28/75 WT lnt. Cl D02g 1/16, D02g 3/36 Field of Search 28/l.4, 72.12, 75 WT References Cited UNITED STATES PATENTS 10/1957 Head 28/75 WT 9/1963 Salyer et a1. 28/1.4 3/l969 Gage 28/72.12 X

3,675,623 7/1972 Taylor 3,701,248

28/l.4 X 10/1972 Gray 28/l.4 X

[57] ABSTRACT A synthetic fiber finish which provides improved processing performance, heat stability, and the like, and comprises a heat stable, hydrophobic fatty acid ester lubricant a heat stable, hydrophilic antistat of an alkoxylated polyhydric alcohol-fatty acid ester or an alkoxylated alcohol ester; and a heat stable, hydrophilic emulsifier comprising alkylene oxide condensate of polyhydric alcohols and/or long chain fatty acid esters or alkylene oxide condensates of an alkaryl hydroxyterminated compound.

2 Claims, No Drawings PROCESS FOR STEAM JET TEXTURING A COATED YARN BACKGROUND OF THE INVENTION Synthetic fibers, such as filaments, yarns, and the like, are often subjected to fairly rigorous processing steps, e.g., high speeds during which the fibers are in frictional contact with hard surfaces, such as draw rolls, thread guides, and other like fiber wear and fiber stress contact points which take their toll, particularly as to unprotected filaments or yarns. Another typical rigorous processing step involves fluid and/or mechanical yarn bulking, such as steam-jet bulking, at high temperatures. In the case of yarn earmarked for carpeting, there are the additional stresses and strains involved in tufting, for instance, which can seriously affect the wear characteristics and strength of the yarn. Other factors involved in the manufacture of synthetic yarns are the static charges which are created during processing, such as those associated with contact between the yarn and the aforementioned metal guides, draw rolls, etc.

To minimize wear and tear, heat damage, accumulation of static charges, and other like processing headaches, it has been found advantageous to enhance interfilament friction characteristics and fiber bundle cohesion, generally by the use of finishes; of course, these finishes must be compatible with the filamentary substrate and not have any adverse effect on the appearance of the fibers, on their dyeability, and other like properties. A typical adverse effect created by an incompatible or improper finish is loss of fiber strength; another undesirable effect is the inability to achieve an adequate moisture level or require the presence of too high a moisture level, e.g., above equilibrium moisture levels, prior to processing, whichare not only detrimental to processability but which could result in molecular disorientation and/or chemical breakdown in the polymer structure, particularly at elevated temperatures, such as those experienced during steam jet bulking.

Needless to say, much thought and many hours of research have been expended in search of finish compositions having the desirable properties hereinbefore discussed. Frustration has been rampant. According to the present invention, however, a fiber finish composition has been discoveredwhich is very effective in providing a ready and practical solution to the long-standing problems which have plagued the art.

THE INVENTION The present invention relates to a novel fiber or yarn finish which manifests improved processing performance as well as stability and durability, especially at elevated temperatures such as those encountered during steam jet bulking. More particularly, the instant discovery concerns synthetic fibrous materials, such as filaments and yarns, having a finish including a heat stable, hydrophobic lubricant comprisinga monoor dior triester of an aliphatic C C carboxylic acid, branched or straight chain, and a polyhydric aliphatic alcohol C C branched (e.g., neoalcohol) or straight chain; a heat stable, hydrophilic antistat comprising an alkoxylated ester having at least mols alkylene oxide per mol material of a polyhydric aliphatic C C alcohol, branched or straight chain, and an aliphatic C C carboxylic acid, branched or straight'chain, or comprising a lower alkyl or alkoxylated (lower alkyl) alcohol phosphate ester; and a heat stable emulsifier comprising an alkylene (lower) oxide condensate of a branched or straight chain polyhydric C C alcohol or an aliphatic branched or straight chain C C carboxylic acid ester (e.g., long chain fatty acid ester), or both, or an alkylene (lower) oxide condensate of a branched or straight chain polyhydric C C alcohol or an alkylene (lower) oxide condensate of an alkaryl (lower alkyl) hydroxyterminated compound, the emulsifier being preferably a blend of at least two emulsifier condensates, one having a relatively high degree of alkoxylation (e.g., above 6 mols alkylene oxide per mol material) and the other having a relatively low degree of alkoxylation (e.g., below 6 mols per mol material). Solubility in water increases with increased alkoxylation, such as ethoxylation and with larger molecular weight hydrophobes greater degrees of relative alkoxylation are desirable in the combination emulsifier.

Further, according to the instant discovery, an aqueous emulsion of the aforementioned heat stable lubricant, antistat and blend of two emulsifiers, one of relatively high alkoxylation and the other of relatively low alkoxylation, is prepared by admixing these four components and warming same to a temperature in the range of 30C to 40C. The resulting mixture or blend is poured slowly, with agitation, into enough water to make an emulsion of from about 2 to about 25 percent solids, by weight, based upon the total weight of the four components and the water.

Each of the four components is present in the following concentration (weight/weight) with respect to the total weight of all four components:

TABLE I Concentration (w/w) When the emulsifier is a blend of one or more low and one or more high alkoxylated materials, the ratio of low to high materials will be in the range of about 1:9 to 9:1, preferably about 1:3 to 3:1.

Typically, the fibers to be treated with the above aqueous emulsion finish, such as polyamide yarns, homoor copolymers, are best passed through a groove in one end of a capillary tube having the usual bore therethrough which communicates with the groove and a source of the aqueous emulsion, the finish being thus metered on to the yarn at a uniformrate. Surprisingly enough, equilibrium moisture levels of the feed yarn, e. g., from about 4.5 to about 5.2 percent with nylon 6,6 at percent relative humidity or from about 0.2 to 0.6 percent for polyethylene terephthalate yarn at 70 percent relative hunidity are sufficient, when the yarn is to be coated with the finish of the invention and then vigorously processed, e.g., steam jet bulked. Heretofore, higher feed yarn moisture levels, achieved only by the use of special, cumbersome procedures such as packageing supply yarns in plastic bags, were needed to process yarns of the type contemplated herein. This need had not only been obviated, but the remaining advantages heretofore alluded to have been discovered.

The finish solids pickup by the yarn is in the range of about 0.3 to about 1.0 percent (weight/weight) and the resulting moisture level is then increased, in the case of nylon 6,6, to the order of between about 4.5 and about 6.0 percent (weight/weight). After processing the yarn, such as by drawing it and texturing it in a steam jet, the solids retention remains in the range of about 0.3 to about 1.0 (weight/weight).

Generally, the fibers or filaments to be treated are formed into a unified bundle before being treated as described herein, i.e., they are not in a dispersed state. For example, molten polymer streams (incipient filaments) issuing from a spinneret are cooled, thus forming filaments which are then combined into bundles or yarns, by directing the streams vertically downward through a cooling zone, e.g., a quenching chimney. The present invention contemplates applying a finish before or after the filaments are combined into a bundle or yarn and/or collected. The filaments may be sprayed with a mist or fog of the novel aqueous emulsion herein described. Alternatively, the yarn may be wiped with the finish by the use of conventional finish rolls dipped into a pan containing the aqueous finish, the rolls generally being part of the take-up equipment and normally made of stainless steel, carborundum, glass or other like inert material. Slow speed rotation of the rolls usually transmits a small but effective amount of the finish to the filamentary substrate and the thustreated filaments are subsequently collected in an orderly manner for further processing.

By way of illustration, a typical steam jet bulking unit suitable for use on the yarns having the spin finish of the present invention is taught in US. Pat. No. 3,380,242 and comprises, generally, a T-shaped, tubular apparatus with the yarn being channeled through the double limbs of the T. Hot steam or hot air from a header is introduced into the single limb of the T and is directed to impinge, at high velocities, on the yarn traveling through the double limb, the area within which impingement takes place being usually termed a bulking chamber. Yarn thus bulked is taken up on a windup. The yarn may be pre-twisted, e.g., S. or Z twists, as desired, before being fed to the T-shaped steam jet bulking unit. It may even been twisted prior to applying the spin finish.

The temperatures and pressures at which the steam is supplied to the jet bulking apparatus may vary considerably. Steam temperatures in the range of about 120C to about 170C, or even higher, are contemplated herein; depending upon the speed of travel of the yarn and the type of bulking desired, steam pressures in the range of about l5 pounds to about l00 pounds (gauge), or even higher, may be employed. Often superheated steam at temperatures of 300C to 400C are desirably employed in steam jet bulking operations.

The present invention will best be understood from the examples which follow, all of which are intended to be illustrative only and are not meant to unduly limit the scope of the invention:

EXAMPLE I A continuous filament nylon 6,6 melt spun yarn (freshly spun) having a denier of 8,600 and 136 filaments, the yarn being made of a hexamethylene adipamide is passed through the groove in one end of a capillary tube at the rate of 100 yarns per minute. Through the capillary tube bore and emptying into the groove in contact with the yarn carried by the groove is a 10 percent aqueous emulsion of a finish composition having the following solids components:

1. A polyethylene glycol (400 molecular weight) based diester of 2-ethyl hexanoic acid 45 percent by weight. (Lubricant) 2. Polyoxyethylene (23) glycerol laurate 15 percent by weight. (Antistat) 3. Polyoxyethylene (25) hydrogenated castor oil 15 percent by weight. (Low alkoxylated emulsi- The aqueous emulsion is prepared by mixing components (1) through (4) and warming same at 35C, the resulting blend being poured slowly, with agitation, into the water to provide an aqueous emulsion having a solids (finish) concentration of 10 percent by weight. The yarn pickup of finish is 0.5 percent (weight/weight) and the resulting moisture level is 5.0 percent (weight/- weight). Subsequent drawing and steam jet bulking of the yarn, having the finish thereon, in a steam bulking apparatus of the type described in US. Pat. No. 3,380,242, at a rate of 335 yards per minute, the jet being supplied with steam at pounds per square inch (pressure) and 340C, results in a well-bulked yarn having wool-like appearance and feel. The bulked yarn has a denier in its bulked state of 2,600, and is very suitable for use as a carpet yarn. Finish retention after bulking is about 0.5 percent (weight/weight).

EXAMPLE ll Example I is repeated in every essential respect with the exception that the 10 percent aqueous emulsion has the following solids composition:

1. Hexadecyl stearate 50 percent by weight (Lubricant) 2. Trimethylolethane triisostearate 10 percent by weight (Lubricant) 3. Polyoxyethylene (25) hydrogenated castor oil glycerides 25 percent by weight (Emulsifier) 4. Polyoxyethylene (5) dodecyl alcohol phosphate neutralized with potassium hydroxide to a pH of 7.0 15 percent by weight (Antistat) Finish retention on the yarn before and after bulking is about the same, viz., about 0.5 percent (weight/- weight).

EXAMPLE lll Example I is repeated in every essential respect with the exception that the poly(hexamethylene adipamide) is a copolymer containing about 5 mol percent caprolactam.

EXAMPLE 1v Example I is repeated in every essential respect with the exception that yarn is made of poly(epsilon caproamide) i.e., nylon 6, homopolymer. The finish composition is:

l. Trimethylolpropane tripelargonate 50 percent by weight (Lubricant) 2. Polyoxyethylene (4) nonylphenol 20 percent by weight (low alkoxylated emulsifier) 3. Polyoxyethylene (30 nonylphenol 15 percent by weight (high alkoxylated emulsifier) 4. Sodium heptylphosphate l5 percent by weight (Antistat) As suggested hereinbefore, typical homoand copolymers within the purview of the present invention are: polyacrylonitriles, cellulose triacetates, acrylic copolymers, polyureas, polyamides, polyesters, and the like. More specifically, fiberforming homopolymers and copolymers within these categories are: polyamides of alkanedioic acids with diaminohydrocarbons, such as poly(decamethylene adipamide), poly(tetramethylene sebacamide), and the like; poly(epsiloncaproamide) [nylon 6]; polyesters of terephthalic acids and glycols, such as poly(ethylene terephthe), and copolymers with other dicarboxylic radicals, e.g., the adipate, sebacate, isophthalate, and the like. These poly mers are particularly suited for making carpet yarns.

As used herein typical lubricants are hexadecyl stearate, 2-ethylbenzylstearate, polyethylene glycol (400) di (2-ethylhexate), trimethylolpropane tripelargonate, trimethylolethane tristearate, soybean oil triglycerides and the like. Typical antistats are polyoxyethylene (20) sorbitan monostearate,

polyoxyethylene (40) sorbitan hexaoleate,

polyoxyethylene (30) glyceryl laurate polyoxyethylene (5) C to C blend alcohol phosphate,

C C blend alcohol phsophate, and the like.

Typical emulsifiers, useable alone and in combination, are

polyoxyehtylene (2) stearyl alcohol,

polyoxyethylene (3) lauric acid,

polyoxyethylene sorbitan mono-oleate,

polyoxyethylene (4) nonyl phenol,

polyoxyethylene (l2) octyl phenol, and the like.

Alkylene oxide and lower alkylene oxide as used herein is inclusive of ethylene oxide, propylene oxide and the butylene oxides with the preferred alkylene oxide being ethylene oxide. Lower alkyl as used herein is inclusive of C, to C alkyl radicals (methyl through decyl, inclusive).

Pursuant to statutory requirements, there are described above the invention and what are now considered its best embodiments. It should be understood, however, that the invention can be practiced otherwise than as specifically described, within the scope of the appended claims.

What is claimed is:

l. A process for hot fluid texturing a polyamide or polyester yarn comprising coating said yarn at equilibrium moisture condition with an aqueous emulsion which comprises (1) about 20 to about percent of a heat stable, hydrophobic lubricant constituted by an ester of an aliphatic Cg-Cug carboxylic acid, and a polyhydric aliphatic alcohol C C (2) from about 10 to about 30 percent of a heat stable, hydrophilic antistat, and (3) from about 10 to about 60 percent of a heat stable emulsifier comprising a lower alkylene oxide condensate, the percentages of all components being by weight, based upon the weight of the total solids content of the finished composition; andthereafter steam jet texturing said yarn.

2. The process of claim I wherein the yarn comprises poly(hexamethylene adipamide) having an equilibrium moisture level at 70 percent relative humidity of about 

2. The process of claim 1 wherein the yarn comprises poly(hexamethylene adipamide) having an equilibrium moisture level at 70 percent relative humidity of about 4.5 to 5.2 percent. 